Machine for mixing concrete and the like



Aug. 18, 1931. A. G. REED 1,819,756

MACHINE FOR MIXING CONCRETE AND THE LIKE Filed May 20, 1929 2 Sheets-Sheet 1 I I i Filed May 20, 1929 2 Sheets$heet 2 INVENTOR will!!!IIIIIIfI/Ilfl/IIIIIIIA Patented Aug. 18, 1931 UNITED STATES PATENT OFFICE ARTHUR G. REED, OF SWISSVALE, PENNSYLVANIA, ASSIGNOR TO MCCRADY BROTHERS-- COMPANY, OF BRADDOCK, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA MACHINE FOR MIXING CONCRETE AND THE LIKE Application filed May 20, 1929. Serial No. 364,345.

This invention relates to mixing machines, and more particularly to a mixing hopper for mixing and delivering material tov a concrete mixing machine.

a The ordinary practice of mixing concrete has been to dump separately the cement, sand, and gravel into the mixing machine, together with water. The result of this practice is that the cement has a tendency to ball up, thereby necessitating running the mixing machine for a ling time in order to break u this balled cement, and sometimes even wit prolonged mixing the wet balled-up cement would not mix properly with the sand and gravel.

In accordance with my invention, I pro-.

vide a mixing hopper which gives the sand, gravel, and cement a preliminary mixing before they are delivered to the mixing machine proper. The sand and gravel are fed in a stream from the mixing hopper and at the same time a stream of cement is mixed with the material being delivered from the hopper. In this way, there is a thorough 2 mixing of all of the materials used in forming the concrete and there is little or no tend-" ency for the cement to ball-up, as in the case where the cement is added separately to the mixer.

In the accompanying drawings which illustrate two present preferred embodiments of my invention,

Figure 1 is a front elevation of the mixing opper, igure 2 is a plan view,

Figure 3 is a view corresponding to Fig. 1,

of a modified form of mixing hopper,

Figure 4 is a section taken on the line IVIV of Fig. 3, and

s Figure 5 is a central vertical section of the mixing hopper shown in Fig. 3.

Referring to Figs. 1 and 2, the mixing hopper 2 is of general cone shape. The hopper is braced by braces 3 and 4 which are riveted to the hopper as indicated at 5. Within the hopper there is arranged a tube 6, having its upper end 7 and its lower end 8 flared for the easy reception and delivery of cement. The tube 6 is held in position by clamps 9, which cooperate with the braces 3 and 4. The clamps 9 are secured to the braces 3 and 4 as indicated at 10. A gate 11 is provided for controlling the flow of material from the hopper. As shown, the gate is pivotally mounted at 12 to the lower end of the hopper 2. The position of the tube 6 relative to the outlet 13 of the hopper may be adjusted by loosening the nuts 10, raising or lowering the tube, and again tightening the nuts. A supply chute 14 is arranged 00 above the upper end of the tube 6 for supplying cement to the tube.

When in use, sand and gravel are supplied to the hopper 2 while the gate 11 is closed. When the correct charge of sand and gravel is in the hopper, the gate 11 is opened and cement is supplied to the tube 6 from the supply: chute 14. The sand and gravel flowaround the lower end 8 of the tube 6 in a stream and are delivered from the outlet 13 of the hopper to the mixing machine (not shown). A stream of cement is at the same time, delivered from the lower end of the tube 6 to the stream of sand and gravel flowing from the outlet of the hopper. In this way, there is. a thorough mixing of all of the materials of the cement batch with little chance of the cement ballingup or failing to thoroughly mix Wlthntl'lfi other materials. so

The mixing hopper 2 is supported in a position so as to deliver the material flowing from the outlet 13 to the mixer by any desired means. It may be supported from above by a crane or may have a separate 3:; support restingon the ground which supports the mixing hopper from below.

In the modified form of mixinghopper shown in Figs. 3, 4, and 5, corresponding parts have been designated with the same reference numerals with an a suflixed thereto. The modified mixing hopper is of the same general construction as that described above, but is provided with a partition 15 which divides the hopper into two compartments 16 and 17 for sand and gravel. The sand is supplied to the compartment 16 through a chute 18, and the gravel is supplied through a chute 19. The partition 15 terminates above the outlet 13a of the hopper and above the lower end 8a of the tube 6a.

The tube 6a contains a pipe 20 provided with openings 21 as indicated in F ig. 5. A fluid such as compressed air is supplied to the pipe 20 through a connection 22. The fluid supplied to the pipe 20 sprays out through tke openings 21 and overcomes any tendency f the cement to stick in the tube 6a.

In the modified mixing hopper shown in Figs. 3, 4:, and 5, there is provided a partition 15 for dividing the hopper into compartments, and a pipe 20 for preventing the cement from sticking in the tube 6a. In some cases, it is not necessary to divide the hopper into compartments. The pipe for supplying fluid to the tube may be used either with or without the partition [or dividing the mixing hopper into compartments.

I have illustrated and described two present preferred forms of my invention. It is to be understood, however, that the inven tion may be otherwise embodied within the scope of the following claims.

Iclaim:

1. A device for mixing and delivering concrete to a mixing machine, comprising a frustro-conical hopper adapted. to receive sand and gravel and deliver them in an annular stream,and a concentric tube within the hopper adapted to receive cement and deliver it in a stream to and surround it by the sand and gravel.

2. A device for mixing and delivering concrete to a mixing machine, comprising a frustro-conical hopper adapted to receive sand and gravel and deliver them therefrom in an annular stream, a concentric tube for cement arranged within the hopper and having its lower end above the discharge opening of the hopper, means for adjusting the height of the tube relative to the discharge opening, and means for controlling the flow of material from the hopper.

3. A device for mixing and delivering concrete to a mixing machine, comprising a frustro-conical hopper adapted to receive sand and gravel and deliver them therefrom in an annular stream, a concentric tube for cement arranged within the hopper and having its lower end above the discharge opening of the hopper, the'upper end of the tube the hopper, a concentric tube within the hopper having its lower end above the outlet of the hopper, means for supplying cement to said tube, and means for adjusting the height of the tube relative to the outlet of the hopper.

5. A device for mixing and delivering concrete to a mixing machine, comprising a frustro-conical hopper having a partitionv therein dividing the hopper into compartmentsfor receiving sand and gravel and delivering them in streams to the outlet of the hopper, a tube for delivering cement arranged concentrically within the hopper with its lower end above the hopper outlet, means for adjusting the tube to vary its height relative to the hopper outlet, said partition terminating above the lower end of said tube, and means for controlling the flow of material from the hopper.

6. A device for mixing and delivering concrete to a mixing machine, comprising a hop per for receiving and delivering sand and gravel in an annular stream to a mixing machine, a concentric tube within the hopper for delivering cement in a stream to and surround it by the stream of sand and gravel, said tube having a substantially unobstructed opening at its upper end for receiving the cement and means connected to a source of compressed air for introducing compressed air into said tube to prevent cement sticking therein. I

7. A device for mixing and delivering concrete to a mixing machine, comprising a hopper for receiving and delivering sand and my hand.

' ARTHUR G. REED.

extending above the top of the hopper, the

upper end of the tube being flared, and means for controlling the flow of material from the hopper.

4. A device for mixing and delivering concrete to a mixing machine, comprising a frustro-conical hopper having a partition therein dividing the hopper into compartments for receiving sand and gravel and delivering them to the outlet of the hopper, the partition terminating above the outlet of 

